HTML, CSS, JS and JAVA corrections

[Ludy87]

Description

• Missing HTML tags were added and the style was adjusted.
• The currentPage attribute was added for login and account in the AccountWebController.
• Darkmode.js has been adapted for the drop-down menu in the login.
• The style sheet for outsourced to files.

Take time to examine the changes.

Checklist:

• I have read the Contribution Guidelines
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings

Contributor License Agreement

By submitting this pull request, I acknowledge and agree that my contributions will be included in Stirling-PDF and that they can be relicensed in the future under the MPL 2.0 (Mozilla Public License Version 2.0) license.

(This does not change the general open-source nature of Stirling-PDF, simply moving from one license to another license)

[Frooodle]

You give me some nightmare PRs to review 😂

[Ludy87]

I can't help it, it's like an accident, I just couldn't look away. But I need another day or two to correct things.

[Frooodle]

Generally speaking raising a PR before changes are finished isnt the best, It sends us all emails but it also uses up the free minutes on the github action bots
OSS software only gets a set amount of free github action server time per month

[Ludy87]

Sorry I used up your resources and flooded your email inbox.

The PR is ready to be audited.